From 4cefa1b830a47385d15f5285c41a6201fed1047e Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Wed, 24 Oct 2012 21:22:23 +0000
Subject: [PATCH] vdisk_fsync() fixes and cleanups

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4567 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/dev_handlers/scst_vdisk.c | 100 ++++++++++++++++++++++-------
 1 file changed, 77 insertions(+), 23 deletions(-)

diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index d32218a12..383e0bf39 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -3251,7 +3251,30 @@ static enum compl_status_e vdisk_exec_prevent_allow_medium_removal(struct vdisk_
 	return CMD_SUCCEEDED;
 }
 
-static int vdisk_fsync(struct vdisk_cmd_params *p, loff_t loff,
+static int vdisk_fsync_blockio(struct vdisk_cmd_params *p, loff_t loff,
+	loff_t len, struct scst_device *dev, gfp_t gfp_flags,
+	struct scst_cmd *cmd, bool async)
+{
+	int res = 0;
+	struct scst_vdisk_dev *virt_dev = dev->dh_priv;
+
+	TRACE_ENTRY();
+
+	/**
+	 ** !!! CAUTION !!!: cmd can be NULL here! Don't use it for
+	 ** anything without checking for NULL at first !!!
+	 **/
+
+	EXTRACHECKS_BUG_ON(!virt_dev->blockio);
+
+	res = vdisk_blockio_flush(virt_dev->bdev, gfp_flags, true,
+		cmd, async);
+
+	TRACE_EXIT_RES(res);
+	return res;
+}
+
+static int vdisk_fsync_fileio(struct vdisk_cmd_params *p, loff_t loff,
 	loff_t len, struct scst_device *dev, gfp_t gfp_flags,
 	struct scst_cmd *cmd, bool async)
 {
@@ -3266,16 +3289,7 @@ static int vdisk_fsync(struct vdisk_cmd_params *p, loff_t loff,
 	 ** anything without checking for NULL at first !!!
 	 **/
 
-	/* It should be generated by compiler as a single comparison */
-	if (virt_dev->nv_cache || virt_dev->wt_flag ||
-	    virt_dev->o_direct_flag || virt_dev->nullio)
-		goto out;
-
-	if (virt_dev->blockio) {
-		res = vdisk_blockio_flush(virt_dev->bdev, gfp_flags, true,
-			cmd, async);
-		goto out_check;
-	}
+	EXTRACHECKS_BUG_ON(virt_dev->blockio);
 
 	file = virt_dev->fd;
 
@@ -3290,7 +3304,6 @@ static int vdisk_fsync(struct vdisk_cmd_params *p, loff_t loff,
 #endif
 #endif
 
-out_check:
 	if (unlikely(res != 0)) {
 		PRINT_ERROR("sync range failed (%d)", res);
 		if (cmd != NULL) {
@@ -3299,14 +3312,51 @@ out_check:
 			else
 				scst_set_cmd_error(cmd,
 					SCST_LOAD_SENSE(scst_sense_write_error));
-			if (async) {
-				cmd->completed = 1;
-				cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT,
-					scst_estimate_context());
-			}
 		}
 	}
 
+	if (async) {
+		if (cmd != NULL) {
+			cmd->completed = 1;
+			cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT,
+				scst_estimate_context());
+		}
+	}
+
+	TRACE_EXIT_RES(res);
+	return res;
+}
+
+static int vdisk_fsync(struct vdisk_cmd_params *p, loff_t loff,
+	loff_t len, struct scst_device *dev, gfp_t gfp_flags,
+	struct scst_cmd *cmd, bool async)
+{
+	int res = 0;
+	struct scst_vdisk_dev *virt_dev = dev->dh_priv;
+
+	TRACE_ENTRY();
+
+	/**
+	 ** !!! CAUTION !!!: cmd can be NULL here! Don't use it for
+	 ** anything without checking for NULL at first !!!
+	 **/
+
+	/* It should be generated by compiler as a single comparison */
+	if (virt_dev->nv_cache || virt_dev->wt_flag ||
+	    virt_dev->o_direct_flag || virt_dev->nullio) {
+		if (async) {
+			cmd->completed = 1;
+			cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT,
+				scst_estimate_context());
+		}
+		goto out;
+	}
+
+	if (virt_dev->blockio)
+		res = vdisk_fsync_blockio(p, loff, len, dev, gfp_flags, cmd, async);
+	else
+		res = vdisk_fsync_fileio(p, loff, len, dev, gfp_flags, cmd, async);
+
 out:
 	TRACE_EXIT_RES(res);
 	return res;
@@ -3907,6 +3957,7 @@ static int vdisk_blockio_flush(struct block_device *bdev, gfp_t gfp_mask,
 		bio->bi_private = cmd;
 		bio->bi_bdev = bdev;
 		submit_bio(WRITE_FLUSH, bio);
+		goto out;
 	} else {
 #else
 	{
@@ -3924,17 +3975,20 @@ static int vdisk_blockio_flush(struct block_device *bdev, gfp_t gfp_mask,
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37)
 out_rep:
-#else
-	if (async && (res == 0)) {
-		cmd->completed = 1;
-		cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT,
-			scst_estimate_context());
-	}
 #endif
 	if ((res != 0) && report_error)
 		PRINT_ERROR("%s() failed: %d",
 			async ? "bio_alloc" : "blkdev_issue_flush", res);
 
+	if (async && (cmd != NULL)) {
+		cmd->completed = 1;
+		cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT,
+			scst_estimate_context());
+	}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37)
+out:
+#endif
 	TRACE_EXIT_RES(res);
 	return res;
 }